/*
 * File     : ConstantIntegerParameter.java
 * Created  : 19 Dec 2011
 *
 * Copyright © 2011 Matthew Wilson (mj. {my-surname} .uk {at} gmail.com)
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package com.googlecode.dni.internal.call;

import org.objectweb.asm.MethodVisitor;
import org.objectweb.asm.Opcodes;


/**
 * Special parameter implementation to hold a constant long to a native
 * call.
 *
 * @author Matthew Wilson
 */
final class ConstantLongParameter extends Parameter
{

    private final long value;


    /**
     * @param value
     *            the value to pass into the native method
     */
    ConstantLongParameter( final long value )
    {
        this.value = value;
        setNativeType( 'J' );
    }

    /**
     * {@inheritDoc}
     */
    @Override
    int getJavaVarSlots()
    {
        return 0;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    void writeGetParameter( final MethodVisitor methodVisitor )
    {
        if ( this.value == 0 )
        {
            methodVisitor.visitInsn( Opcodes.LCONST_0 );
        }
        else if ( this.value == 1 )
        {
            methodVisitor.visitInsn( Opcodes.LCONST_1 );
        }
        else
        {
            methodVisitor.visitLdcInsn( this.value );
        }
    }

    /**
     * {@inheritDoc}
     */
    @Override
    void writeReturnParameter( final MethodVisitor methodVisitor,
                               final int returnVarIndex )
    {
        throw new UnsupportedOperationException();
    }

}
